Emergency-brake for sawmill-carriages.



No. 787,874. PATENTED APR. 18, 1905. j

J. L. GRAHAM.

EMERGENCY BRAKE FOR SAWMILL CARRIAGES.

APPLICATION FILED DEG.27,1904.

4 SHEETS-SHEET 1.

WITNESSES: j Z/m/ INVENTOR yw p/flax ATTORNEY I PATENTED APR.18, 1906.

J. L. GRAHAM.

EMERGENCY BRAKE FOR SAWMILL CARRIAGES.

APPLICATION FILED DEG.27,190-1.

INVENTOR WITNESSES:

J. L. GRAHAM.

EMERGENCY BRAKE FOR SAWMILL GARRIAGES.

APPLICATION FILED DEG.27,1904.

4 SHEETS-SHEET 3.

WITNESSES: g W 1/ INVENTOR a? BY A M ATTORNEY No. 787,374. PATBNTED APR.18, 1905.

J. L. GRAHAM. EMERGENCY BRAKE FOR SAWMILL GARRIAGES.

APPLICATION FILED DEC 27, 190-1.

4 SHEETSSEEET 4.

WITNESSES: INVENTOR ATTORNEY UNTTED STATES Patented April 18, 1905.

ATENT @FFTCE.

JOHN L. GRAHAM, OF HAAKlVOUl), HlCIllGA N.

SPECIFICATION forming part of Letters Patent No. 787,374, dated April18, 1905, Application filed December 2'7, 1904. Serial No. 238,487.

To u/f II/II)III- it may concern.-

Be it. known that I, Join? L. GRAHAM, a citizenof the United States,residing at Haakwood, in the county of Cheboygan and State of Michigan,have invented certain new and useful Improvements in Emergency-Brakesfor Sawmill-(Iarriages; and I do hereby declare the following to be afull, clear, and exact description of the invention, such as will enableothers skilled in the art to which it appertains to make and use thesame.

My invention relates to a safety device for quickly stopping asawmill-carriage, and is especially adapted to that class ofsawmillcarriages operated by a device commonly known as a steam-feed,consisting in a long horizontal steam-cylinder bolted to the millstructure and having a piston to which is attached a long piston-rod,the outer end of the piston-rod being connected to the sawmill-carriageto traverse it rapidly back and forth.

lit has frequently occurred that an accident to the valve which controlsthe admission of steam to the steam-feed cylinder causes the sawyer tolose control of the carriage, resulting frequently in a wreck andserious injury to the operators who ride on the carriage.

This invention embodies means whereby the piston-rod of the steam-feedwill be instantly and powerfully clamped and brought to rest as soon asthe sawyer releases his hold on the lever that controls the movement ofthe sawmill-carriage.

The invention is illustrated in the accompanying drawings, in which-Figure l is a front end view of the steamfeed cylinder and clampingdevice. Fig. 2 is a side elevation of the same. Fig. 3 is a top planview, and Fig. l is a perspective, showing the levers by which theclamping device is operated.

A is any ordinary steam-feed cylinder, such as is now in common use, andB is the pistona'od, to the outer end of which the sawmill-carriage issecured. The carriage is omitted from the drawings for the sake of'clearness.

U is the sawyers lever, which, as commonly used, operates only to admitsteam to either end of the cylinder A by properly actuating theadmission-valve of the cylinder. 7

In this invention I employ the lever C to perform the additionalfunction of a safetylever, whereby the steam-feed rod may be forciblygripped and brought to rest as soon as the sawycr releases his hold onthe lever. This safety-feed may be embodied in the le ver (3 in variousways; but I have illustrated only one construction to accomplish thedesired results. This device is illustrated in Fig. 1, where the handleC is made hollow and provided with a vertically-movable hand piece orgrip C, which rests like a cup on the top of the lever. A spring (1* isinterposed between the top of the lever and the grip C and is normallycompressed by the weight of the sawyers hand resting upon it. \Vhen socompressed, the grip (IV pushes down on the rod C within the lever (,7and operating through the bellcrank lever l) operates the steam-valve E,which may be of any suitable construction to admit steam through thepipe F to the lower end of a short steam-cyliiuler G, thereby pushingupthe piston lliof the cylinder G and its red ll. To the upper entfof therod Ii is fastened a l avy metal st rap l, carrying a clamping-shoe J,adapted to [it the upper circumference of the steam-feed rod B.

\Vhen the sawyers hand is released from the grip C, the spring rises,pulling up the rod U and drawing back the bell-crank fever ,1), thusopening the pipe F to exhaust and admitting steam to the pipe K, whichcommunicates with the cylinder (l above the piston H. The piston-rod Itand the clampingshoe J are immediately pulled down, and the shoe Jclamps the piston-rod down tightly upon the lower block L, quicklystopping the movement of the rod.

To further increase the ellicieney of the device, I have added to theclamping means above described a device for shutting off the supply ofsteam to the steam-feed cylinder simultaneously with the operation ofthe clamping device.

In Fig. 1, M represents the. steam-main through which the steam issupplied from the boilers to the Valve of the steam-feed cylinder A. Thepipe connections are not shown, as their arrangement varies underdifferent conditions.

I provide in the pipe M a suitable shut-01f valve N, having a valve-rodN connected to a bell-crank lever O, the other end of the lever beingconnected to a bell-crank leverP, which in turn is pivoted to thedownwardly-extending arm of a bell-crank lever Q and the other end ofwhich is pivoted to the piston-rod H. The lever Q is carried by asuitable pivoted link R.

The operation of the device is as follows: When the operator releaseshis hold on the grip C and the piston-rod II and the shoe J drop aspreviously described, the bell-crank lever Q operates the link P and thebell-crank lever O to move the valve-stem N of the valve N, therebyshutting off the supply of steam through pipe M.

While I have described and illustrated cer tain specific mechanisms foraccomplishing the desired result of gripping the steam-feed rod when thesawyer releases his hold on the controlling-lever, I do not desire toconfine myself to these particular constructions.

What I claim as my invention, and desire to secure by Letters Patent, isas follows:

1. The combination with the piston-rod of a steam-feed of a clampadapted to rip said piston-rod a sawyers operatingever; a movablehandpiece carried by said lever and means connecting said handpiece tosaid clamp and adapted to automatically actuate said clamp to grip saidpiston-rod when the sawyer s hand is removed from the operatinglever.

2. The combination with the piston-rod of a steam-feed of a clampadapted to grip said piston-rod a valve in the steam-pipe leading to thesteam-feed; a sawyers operating-lever; a movable handpiece carried bysaid lever; and means connecting said handpiece, clamp and valve, saidmeans being adapted to automatically actuate said clamp to grip thepiston-rod and to actuate said valve to shut off steam in said mainsteam-pipe when the sawycrs hand is removed from the operating-lever.

3. The combination with the piston-rod of a steam-feed of a clampadapted to grip said piston-rod; a sawyers operating-lever; a capslidably mounted on top of said operating lever; a bell-crank leverpivotally mounted on said operating-lever; and means connectin said capwith said bell-crank lever; a valve actuated by said bell-crank lever; a

cylinder with a movable piston and means connecting said movable pistonwith said clamp and adapted to actuate the clamp to grip the saidsteam-feed piston-rod when the sawyers hand is removed from saidoperating-lever.

4. The combination with a steam-feed piston-rod; of a clamp adapted togrip said piston-rod; a sawyers operating-lever; a cap slidably mountedon top of said operatinglever; a bell-crank lever pivotally mounted onsaid operating-lever; a movable rod connecting said cap with saidbell-crank lever; a valve actuated by said bell-crank lever; a cylinderwith a movable piston and means for connecting either end of saidcylinder successively with said valve; and means connecting said pistonwith said clamp.

5. The combination with a steam-feed piston-rod, of an operating-lever;a cap mounted on said operating-lever; a bell-crank lever mounted onsaid operating-lever; and means for connecting the cap with saidbell-crank lever; a valve actuated by said bell-crank lever; a cylinderwith a movable piston and means for connecting either end of saidcylinder successively with said valve; a pistonrod secured to saidmovable piston; a clamp comprisinga lower stationary block adapted tosupport said steam-feed piston-rod, and an upper movable block and meansconnecting said movable block with said pistonrod, substantially as andfor the purposes set forth.

6. The combination with a steam-feed cylinder, piston and piston-rod; ofan operating-lever; a valve and means connecting said operating-lever tosaid valve and adapted to actuate said valve; a cylinder having amovable piston and means for connecting either end of said pistonalternately with said valve; a piston-rod secured to said movablepiston;

a clamp adapted to grip said piston-rod and I means for connecting saidpiston-rod with said clamp; together with a valve in the steam-supplypipe of said steam-feed cylinder and means connecting said movablepiston to said valve, for closing said valve when the piston moves down,substantially as described.

In testimony whereof I affix my signature in presence of two witnesses.

JOHN L. GRAHAM.

Witnesses:

J. STANLEY SEE, J. R. MANsFIELD.

